join standalone table (featureset) to geographic features - how to???

I have a featureset i created from a dataset using the featureset.fromjson(myjsondataset).

I need to know how to join this data with geographic features in Esssentials in a workflow based on a common field.  I would like to be able to show up in maptips and the results table.

Any ideas on this.  its basically a tablejoin in essentials.

Jeff