How long have Focus Group and Neighbour Group people been in contact overall?

As per other domains

What is the overall time frame when the largest number of people had the most opportunities for interaction?

As per other domains

How long have Focus Group and Neighbour Group people practised exchange for?

The Williams ethnography has data from 1920, and six generations will have been claimed from then. So if we say each generation is about 20 years, then contact has been ongoing since at least 1800. But I imagine contact has been ongoing for much longer than that.

What is the time frame when the largest number of people had the most opportunities for interaction in exchange?

There is no evidence that the domain of social exchange and marriage as a domain of contact has been disrupted in the present or past. So the same as above.

How long have Focus Group and Neighbour Group peoples been forming families with each other for?

Generations. See response to other domains.

What’s the time frame of densest contact between Focus Group and Neighbour Group as far as family formation is concerned?

see above

How long have Focus Group people and Neighbour Group people worked together for?

As long as they have been forming families

What is the time frame when the largest number of people had the most opportunities for interaction in the labour domain?

As per my other answers

How long have Focus Group and Neighbour Group people been in contact in the local community?

As per other domains, multiple generations.

What is the time frame when the largest number of people had the most opportunities for interaction in the local community?

Since villages were officially formed under the colonial administration in the mid 1960s. The Williams ethnography already mentions villages in the 1910-20s, so at least for the last 100 years people have been living in villages. Perhaps the population increase in the 20th century has also contributed to larger village units becoming a more typical form of local community. Today, people still spend a lot of time in their garden places, and we believe this may have been the more common form of local community prior to the village system (see Kashima 2020: 37-39). Garden places can consist of a couple of nuclear families (see answers in DLB)