Create a reusable part called FLDVIS01 using the source following.  This is will provide autocompletion functionality for field DEPTMENT:
Function Options(*DIRECT)
Begin_Com Role(*EXTENDS #PRIM_PANL *implements #Prim_dc.iMonitorSubject) Defaultpty (Value) Displayposition (1) Height (20) Layoutmanager(#ATLM_1) Left(0) Tabposition (1) Top (0) Width (150)
Define_Com Class(#PRIM_ATLM) Name (#ATLM_1)
Define_Com Class(#DEPTMENT.VisualEdit) Name(#Department) Displayposition(1) Height(20) Marginleft(0) Parent (#COM_OWNER) Tabposition(1) Width(150)
Define_Com Class(#PRIM_ATLI) Name(#ATLI_1) Attachment(Center) Manage(#Department) Parent(#ATLM_1)
Define_Pty Name(Value) Get(GetPropertyValue) Set(SetPropertyValue)
Ptyroutine Name(GetPropertyValue)
Define_Map For(*Output) Class(#prim_alph) Name(#Property)
#Property := #Department
Endroutine
Ptyroutine Name(SetPropertyValue)
Define_Map For(*Input) Class(#prim_alph) Name(#Property)
#Department := #Property
Endroutine
Mthroutine Name(ApplymonitoredValue) Options(*redefine)

• No redefinition required
  Endroutine
  Mthroutine Name(GetValue) Options(*redefine)
• No redefinition required
  Endroutine
  Evtroutine Handling(#Department.KeyPress) Handled(#Handled) Keycode (#KeyCode) Char (#Char)
• If the field isn't full
  If (#Department.CurSize <> #Department.FieldLength)
• If a character entered
  If (#KeyCode = isChar)
  #Com_Owner.PrepareAutoComplete
  If (#Com_owner.CanAutoComplete)
  #Handled := True
  #Com_owner.AutoComplete( #Char )
  Signal Event(ValueChanged)
  Endif
  Endif
  Endif
  Endroutine
  Evtroutine Handling(#Department.Changed)
• Handle all other key presses that might affect the value
  Signal Event(ValueChanged)
  Endroutine
  Mthroutine Name(CanAutoComplete) Help('Can we autocomplete?') Access(*Private)
  Define_Map For(*Result) Class(#prim_boln) Name(#Result)
• If selection doesn't start at the end of the value, autocomplete is not appropriate.
  #Result := (#Department.SelectionEnd = (#Department.Trim.cursize + 1))
  Endroutine
  Mthroutine Name(AutoComplete) Access(*private)
  Define_Map For(*Input) Class(#prim_alph) Name(#Char) Help('Character just pressed on the keyboard')
  Define_Com Class(#prim_nmbr) Name(#Start)
  Define_Com Class(#prim_alph) Name(#Candidate)
  #Start := #Department.SelectionStart
  #Candidate := #Com_owner.PrepareCandidate( #Char )
  #Department := #Com_owner.GetCandidate( #Candidate )
• Set selection to be startposition + 1 to the end
  #Department.SelectionStart := #Start + 1
  #Department.SelectionEnd := #Department.Trim.cursize + 1
  Endroutine
  Mthroutine Name(PrepareAutoComplete) Help('Prepare Selection in the value so that it runs left to right') Access(*private)
  Define_Com Class(#prim_nmbr) Name(#Transition)
• If Start is greater than end, reverse the selection points
  If (#Department.SelectionStart > #Department.SelectionEnd)
  #Transition := #Department.SelectionStart
  #Department.SelectionStart := #Department.SelectionEnd
  #Department.SelectionEnd := #Transition
  Endif
  Endroutine
  Mthroutine Name(PrepareCandidate) Help('Prepare the input value ready for looking up the next candidate') Access(*private)
  Define_Map For(*Input) Class(#prim_alph) Name(#Char) Help('Character just pressed on the keyboard')
  Define_Map For(*Result) Class(#Prim_alph) Name(#Result)
• If selection is the whole word, only use the char supplied by the event
  If (#Department.SelectionStart = 1)
  #Result := #Char.uppercase
  Else
• Get anything to the left of the cursor start position and append the last key press
  #Result := (#Department.substring( 1 (#Department.SelectionStart - 1) ).trim + #Char).Uppercase
  Endif
  Endroutine
  Mthroutine Name(GetCandidate) Access(*private)
  Define_Map For(*Input) Class(#prim_alph) Name(#Candidate)
  Define_Map For(*Result) Class(#prim_alph) Name(#Result)
• If no record found, the last value entered is still the right answer
  #Result := #Candidate
• Find the first record starting with the candidate value
  Select Fields(#Deptment) From_File(Deptab) With_Key(#Candidate) Generic(*yes)
  #Result := #Deptment
  Leave
  Endselect
  Endroutine
  End_Com
  Note how the reusable part only displays a single input box for DEPTMENT. No labels or descriptions are required.
  Open field DEPTMENT and turn to the visualization tab.

Select the option for New Visual Host and the choose FLDVIS01 from the prompt.  DEPTMENT should now appear as follows:

The new Visual_host reusable can now be used as follows:
Define_Com Class(#Deptment.Visualhost) Name(#...)
You might also consider changing the default name of VisualHost to AutoComplete or similar.  This means when it's used on a form you'll see the following:
Define_Com Class(#Deptment.AutoComplete) Name(#...)