Although there are apparently not many breeders who offer Golden Cocker Retrievers, producing this hybrid follows the same variations as any other hybrid: F1, F1B (or F1-B), F2, F2B, F3 and so on. Some breeders will choose to cross smaller individuals to create petite or toy puppies.
The F1 Golden Cocker Retriever is 50% Golden Retriever and 50% Cocker Spaniel (American or English). An F1 Golden Cocker Retriever's characteristics can vary greatly, even among a single litter. There are no guarantees that can be made regarding the F1 Golden Cocker Retriever's personalities, coat style, color, etc, a factor which is known as "instability."
An F1B Golden Cocker Retriever is an F1 bred back to a Cocker Spaniel — which makes the F1b 25% Retriever and 75% Spaniel. The reason that Cocker Spaniels — rather than Retrievers — are used when breeding back to an F1 is usually to make the Golden Cocker Retriever smaller and / or to have a longer coat. (Goldendoodles, which are Golden Retrievers crossbred with Poodles, are produced the same way albeit with the intent of making the Golden Cocker Retriever less of a shedder and more hypoallergenic.)
An F2 Golden Cocker Retriever is the result of two F1 Labradoodles being crossbred, and many of the same instabilities of the F1 tend to remain with F2s. To get to F3 and eventually F7 (which is the first stable multi-generational Golden Cocker Retriever that can be considered for recognition as a pure breed), however, F2s must be produced.
The F3 Golden Cocker Retriever is the first of the multi-generational (or multi-gen) hybrids. Two F2s crossbred produce an F3 and it is the F3 that is said to be the first of the stable generations. Experienced, knowledgeable breeders can exercise some control of multi-generational Golden Cocker Retriever personalities, coat colors and more.
If an F1 Golden Cocker Retriever is bred back to an F1B Golden Cocker Retriever, that is an F2B Golden Cocker Retriever.