Custom connector dynamic querystring params

Product/components used and version/fix level:

Webmethods.io cloud

Detailed explanation of the problem:

I’m trying to make a custom REST connector that queries a backend using a GET with varying query string parameters. I can query on several attributes in the backend. I want to define one resource and one operation for this so I don’t have to put in all posible attributes in the custom connector. Is this possible somehow? Of what I can come up with I have the put in all possible attributes in de connectors GET resource and operation as optional parameters. When I need to filter on a new backend attribute I have to add this to the connector as well.