Rub is related to Soft. Soft is the opposite of Tough. Tough is a different concept from Tender. Tender is related to Sentiment. 
Brother is related to Uncle. Uncle is related to Dad. Dad is related to Parental. Parental is related to Family. 
Rub <--RelatedTo--> Soft <--Antonym--> Tough <--DistinctFrom--> Tender <--RelatedTo--> Sentiment 
Brother <--RelatedTo--> Uncle <--RelatedTo--> Dad <--RelatedTo--> Parental <--RelatedTo--> Family 