Multiple fields in a custom button in a related list

Multiple fields in a custom button in a related list

Hi
I've a problem with custom fields in a button in a related list.. I want one property of the parent entity and the id of the selected child entity. As a result the values are only when I set only one value.

Example:

In a custom Module "Households" is a list of dependent "Persons" I want to add a button to the persons table.
I need BOTH values as a person could be related to more than one household?

Now when I set

HTTP://exmaple.com?a=household.househol-id&b=persons.person-personId
None of the values are set.

but all of the following scenarios DO work. So the variable names seem to be correct and the static values for a and b are los set

HTTP://exmaple.com?a=household.househol-id
HTTP://exmaple.com?b=persons.person-personId
HTTP://exmaple.com?a=household.househol-id&b=1
HTTP://exmaple.com?a=1&b=persons.person-personId


Is there maybe a script to handle this ?
Can someone provide an example?