Group By Taxonomy term on view but show all articles containing it
In my example I have Article with taxonomy term reference field tags and have create following content/terms


2 Tags: test1, test2 
4 articles (2 including test1, 2 including test2)


Create a view of content displaying fields and filter to display articles only


add title field 
add tag field (can exclude it from display)  
format settings > choose grouping field Nr 1. > tags