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I need to add a new field (one more) to the group interface.
What files to use?
Here the files used to show the groups in Jomsocial: components/com_community/templates/jomsocial/layouts/groups
However, you need to hack the core system to add new fields in the groups.
Yes, this folder, the database table.
How else are the folders?
These are the files used in for Event, in the database you can find the community_events table that used in the events.
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