You are on the rite track here. The idea is that you need to link to this same page for all of the groups and just pass in the appropriate id. On this page with the recordset you will need to filter the recordset with this new URL parameter. In your recordset interface at the bottom you should have the option of filtering, choose the id column that your value will match with then specify to filter this column on a URL parameter and enter the name of your parameter, Subgroup.
Then whenever you link to this page with the Subgroup parameter set to a valid id it should filter the recordset and give you only the records from this Subgroup. The link will need to look like your example: