to achieve it you will have to fetch your data using OQL and make a Filter Empty button on top of grid and as it click call same microflow and pass input parameter variable set it value empty and pass to OQL WHERE Condition like WHERE name=empty OR email=empty
also make sure your grid should be refresh every second to show updated/ filtered record according your condition
conditions as many as you want
another option is also using Xpath constraint but it will not be dynamically.. [you can use two data grid also but not professional way so go for OQL first option]