Of course a 'one-place study' is just what it says it is - a detailed look at the people and events in a particular place. What has surprised me (though perhaps shouldn’t have) is the extent to which studying my place has included material from other places too.
The first aspect of this is the extent to which people from my place were involved in other places too. One obvious example is WW1 and WW2. Those of us who did the shared endeavour on WW1 back in 2014 will have come across soldiers whose lives were affected by, and sometimes ended in, other places. There are a number from my place who fought at the Somme, others will have links to other battlefields. 2019 is the 80th anniversary of the start of WW2. I haven’t researched residents from my place in WW2 yet but am sure they will have been involved.
Another example is that of migration, both in and out. Migration within the UK is quite common but look further afield too. One of my OPS residents moved from Middlesex to Springhill via, amongst other places, Brantwood Ontario where he held property. He served in the Canadian cavalry reserves which was tarted up as 'considerable active service abroad' to enhance his reputation in Lancashire. The area around my place saw considerable migration to Utah under the influence of the LDS church whilst Janet Few has discovered that virtually an entire community moved across the pond from her place to found a new community under specific religious principles.
The second aspect is that events in your place can impact on distant places or be reported in them. I idly entered the name of my wider area into Trove (the National Library of Australia's excellent database: https://trove.nla.gov.au/) with no expectations when up popped a reference to a by-election result from the local constituency in 1892. Although a vote in an insignificant part of East Lancs, it was fought largely on Irish home rule and the election of a candidate sympathetic to home rule led to ructions which were reported in far-away Aus.
Both WW1 and migration were the topics of previous shared endeavours and if you missed them first time round the resources are available to members in the members-only area.
So people and events from our one places impact on and are affected by those in other places. Cast your research nets wide!