How to release selection from navigation menu if moved out

Summary:

I have created one VBCS app with navigation menu at the top of page (in shell page) to navigate between the pages as shown below. When I click on flow1 or flow 2 it has to go to one among the 2 pages respectively but when I click on "go to main" then main page has to open and in navigation menu it must not highlight flow2 / flow3 as selected as highlighted below

When I click on "go to main" button it will goto main page but why it is still highlighting flow 3. How can I make that flow3 not to highlight as selected? i.e. underline below Flow 3 must not be present when navigated to main page