From your question what i understood is ,when the fields in third tab are updated that needs to be refreshed and displyed in first tab right ?
Then you should be using the action set on third tab ,On Change with the action as Refresh section .This will refresh the section and you have to call the activity that updates the correspondent content also in the action set of third tab.
Reloading content in other all the tabs normally happens at first and on click of tab, there is no way to refresh it. So I suggest you to use refresh other section in tab1 from tab3 while the change is being made.
Thanks Santosh. But here the issue is we have many fields in third tab to edit and on each field keeping action for refresh section is not an good approach i guess.Let me know if any other suggestions.