Yes it's possible, but without knowing how you've designed your database and what you want to see on each tab, it's impossible to tell you how to set up or even if this is a practical design approach.
Reply back with a description of what you want and maybe someone will be able to make a helpful response.
actually if i wanna put my databases into tab in a single file, those tabs wont have any interconnection relationship at all, its just easier for me to switch between tabs rather than open 3 seperate filemaker files...
Sorry, but that's really not enough information to go on.
Each layout refers to a specific "table" box (called a table occurrence) in your relationships graph. You can only display records from that specified table on your layout or show related records in portals--each portal could be placed on a tab.
First you have to add table occurrences to your relationship graph that link to data in your other files or import the tables from your other files so that you merge them all into a single file. You can use the X operator when linking these so that all records in the other tables "match" and thus your portals can be scrolling windows listing all the records.
However, lack of information from you could be leading me into wrong assumptions that in turn could result in me suggesting a very impractical approach.
What are these unrelated files? (That fact that you want to put them all on the same layout suggests they may in fact be related.)
Do they need to be separate files or could they be merged?
What is the purpose of this database?