Any group of objects can be imported into the current metadata repository from another repository. If an object already exists in the target repository, then it is either skipped or replaced depending on the type of import undertaken. If an object is to be replaced as part of an import, a version of the object is created before its replacement.
To import an object or group of objects select the Tools > Import Metadata Objects menu option. 
A window appears that provides two options, IMPORT or REFRESH. An import will not replace an existing object of the same name. A refresh will version and replace any existing object of the same name.
Enter the connection and a database user name and password that has access to the source metadata repository.
Finally, enter the user name of the metadata repository you want to import from. In most situations, the User Name and Meta Repository would be the same.
However, if you only have read access to a meta-repository, then it may be necessary to log in to the database under a different user name from that of the repository you are trying to import from.
You are not permitted to select the current meta-repository in the Meta Repository field but are permitted to log in using the existing repository username. Once a successful log-on is completed, the contents of the source repository are loaded and the following window appears.
Select an object by double-clicking it or by selecting and using the > button. If an object such as a table is chosen, then any related scripts, procedures, and indexes are also selected. They can be removed if required. A target project can be selected.
Once all required objects are selected, click OK to start the import process.
On completion, a window appears that displays the number of each type of object imported and skipped.
The repository from which you are importing must be the same metadata version as the target repository.