Please refer : Export Excel on Filtered Values in UI Grid - UI Kit | Support Center

Standard OOTB method like Page-Copy doesn't work if we need to use the metadata in the GridMetaData_XXXXXXXX page.

The corresponding pxObjClass Pega-UI-Component-Grid-Filter is a concrete class without a key. Not sure if we can use Obj- methods to use the metadata

Please advise as to how can we use the information on this page using an activity