Yeah, well, the functionality is there but this is also circuitous. From the point of ease of use it would be more intuitive if one could do it when one clicks on "My posts" and had a dark blue "search" menu handy in the usual place.
As an aside: In the left column it says my number of posts is about 1400 but when I click on "My Posts" it says page 1 to 50 of 600 posts? How comes the discrepancy? (Not complaining about a lost opportunity to boast, I know others have lots more