URL routing with types
What is the type of field of family ?
You don't have to enter the domain and language. Just start from family and forward. If family is the title field, write it like this:

{title}/offers/{slug}


if the family field is an element type, do it like this:

{familyField.last().uri}/offers/{slug}


or

{familyField.last().slug}/offers/{slug}


or if it is a title

{title}/offers/{slug}