Item group slicer

Anonymous , first of all you need an independent item group slicer

then you can have meausre like

selected = calculate([meausre], filter(Table, Table,[item group] in allselected( 'item group'[ item group]) ))

not selected =

var _tab = except( all( 'item group'[ item group]) ,allselected( 'item group'[ item group]) )

return

calculate([meausre], filter(Table, Table,[item group] in _tab ))

If you need them with a column(having measure names)  , the create a calculation group 

Need of an Independent Table in Power BI: https://youtu.be/lOEW-YUrAbE

Calculation Groups- Measure Slicer, Measure Header Grouping, Measure to dimension conversion. Complex Table display : https://youtu.be/qMNv67P8Go0