Need to import a text layer into a InDesing file from another one.

Depends on how your documents are created. If your documents are set up page by page (both documents have same number of pages and all pages have same contents, just different translations) then a script such as the following may work for you. (Written in AppleScript).

To use, make sure both documents are open. Receiving document needs to have a layer named the same as the source layer from the target document. In this example, the receiving document is the English document ("Test_English.indd") and the source document is "Test_Spanish.indd". The English document has its text on layer 1 but also has a layer named "Spanish" which corresponds to the layer named "Spanish" in the source document. The "Spanish" layer must be visible and not locked in both documents. Make a duplicate of both documents and save in protected location just in case.

With that, you can copy the following script into AppleScript editor and run (command+R) or save as a Script format from AppleScript editor and run from the script menu in InDesign.

//Script copies all pages from source document to receiving document.

tell application "Adobe InDesign CC 2015"

  tell clipboard preferences

  set paste remembers layers to true

  end tell

--receiving document

  set docRef to document "Test_English.indd"

--gets count of spreads in receiving document

set numSpreads to count of spreads of docRef

--repeats through each page to copy from source document to receiving document

  repeat with i from 1 to numSpreads

  set active document to document "Test_Spanish.indd"

  tell spread i of document 1 to select all

  activate

  copy

  set active document to document "Test_English.indd"

  set active spread of active window to spread i of document 1

  paste

  end repeat

end tell

are those text Frames in the same position on pages, through all documents?