Click ‘+’ at the bottom, a new selector and a new style element. So each selector was added to a new style element. The change is a single style element should be there for each file and thus it can have multiple selectors. Both the earlier version and new implementation are shown below:
Setting the selectors in single style element when the dialog is to be populated with selectors from already existing drawing is in progress yet. More on previous implementation of populating the style dialog can be seen here.
Besides this implementation, I have added buttons to the treeview against each row containing selector. These ‘+’ buttons will be used to add selected objects to existing selectors instead of creating a new one every time, as per need of the user.