Bring back using external sources for runs

Hi there,

I hope you’re doing great.
Maybe I am just blind to the feature, but in the past, before the UI change, one could use for each run external sub-selection - it was helpful when switching between apps - relion->cs->relion->cs. Right now one needs to create another dataset with a subselection to continue with a new subselection.
Would it be possible to point me to the feature or reintroduce it ?