How to search for some topic in a specific subforum?

[MathematicalPhysicist]

I looked at the search option, and I want to search some topic in some subforum, but there isn't such an option. Only to search through tags or poster's name.

Can someone tell me how to search by choosing the appropriate subforum in PF?

Thanks!

 

[Ibix]

If you go to the forum you want to search then click the search button, there's a dropdown (says "everywhere" initially) that includes "this forum" as an option.

 

[anorlunda]

If you click on "search threads" rather than "search everything" an additional parameter field appears for forum/subforum.