If you mean when selecting criteria it is still there but not immediately visible. If you click the in the Value box the Magnifying Glass will appear.

The magnifying glass shows up for Item Code and Warehouse, but when I go to the box for Item Description, it is no longer there. We still have the option of entering freeform information, but not in a manner where we can open the window with the magnifying glass and see multiple item numbers pulled from a search using that function. Specifically, I'm in the Inventory Receipts History Report. It's the same for the Inventory Stock Status Report.

I checked those reports in 4.30 which is the last release with legacy Inventory Management and there are no lookups on the starting and ending Item Description selection fields.  You may have had an enhancement that provided that functionality in your previous version you were using?