How to restore expanded search overlay on Mobile?

[Optic14]

Hi there,

I need to restore this Expanded Search overlay for mobile users:

Because my members cannot search inside an existing topic, when on mobile. If you tap on the Search icon, you go straight to the Full Advanced Search page.

"Search in This Topic" is not available on the Full Advanced Search page.

In XenForo we were able to do this, even on Mobile responsive:

Does anyone know if a plugin exists or a template edit we can do to restore this?

Any help would greatly be appreciated.