Britain, France, the Netherlands, Germany, and Scandinavia are very close to each other geographically, is there any cultural overlap?
“Any” is something of a broad term. Of course there is - there’s also cultural overlap from China, India, the US, and probably the Polynesian states too.
If you mean “significant” overlap, well, each area is different. Sweden and Norway share a hell of a lot, including just-about mutually intelligible languages, probably due to the Swedish Empire having ruled much of Norway.
Dutch has a lot of similarities with German. English has a lot of similarities with Dutch and German, with strong influences from Norman French as well. The accent and dialect of North-East England has some Norwegian overtones.
Latterly, French cuisine has influenced English cooking significantly, so that modern English cuisine is now amazingly good and internationally regarded. In the Netherlands, many cafés are very similar to French ones.
In France, the influence of Anglo-Saxon (including American) culture is huge, exhibited most obviously in adopted words (le picnic, le weekend).
Yet each country is very significantly its own culture. You might want to tighten your enquiry up a bit.
There’s the question of perspective, too. To someone born and raised in Amsterdam, the differences between the cultures of northern/western Europe probably seem pretty clear-cut. But introduce an observer born and raised in, say, East Timor. To the latter, the similarities will initially be much more apparent than the differences.