You can assign an object name to each tab,
then write a script like this:
If the content of some field is X
go to object (first tab)
else if the content of some field is Y
go to object (second tab)
Then you can associate your script as a script trigger to your layout,
choosing "on record load" option.
It's enough: the result is that, when you browse records, every record will select the tab you want to show.
Thank you very much!
That worked perfectly and was easy to do.
I really appreciate your help.