Is there a way to export a group of placeholder meshes that I’ve arranged in my level as one FBX? I want to take it into my 3D package as a guide for modeling the actual mesh that is going in their place.
Maybe I’m missing it, but I thought I’d seen an export option before.
Yes, you can export an object from your level I think it’s from the file menu or something but it’s definitely there.
You can’t export a group of meshes at once. But you can use the merge actor (only in 4.12) and merge those meshes together. It will generate a separate static mesh for you and then you can right click on it in the content browser -> Asset Actions -> Export.
Merge actor is located in Window -> Developer Tools. 
I was able to multiple meshes at once.
Just to clarify, you can export multiple meshes at once by selecting them in the content browser and exporting. That would export them into individual .FBX files. However, OP intends to export a group of meshes that are placed in his game level into a single .FBX file.
I had all meshes in a single FBX file, and that was with 4.11.2
I had 3 static meshes, one I imported and scaled, and the other 2 were UE4 cubes. So when I imported FBX into Blender, there were same 3 meshes.
I can confirm that multi-selecting a group of meshes in a scene and going ‘file -> export selected’ will export the whole group as one .FBX
That is indeed how exporting an asset works. But that is not what OP is after. OP wants to export a **scene **, which one can do by selecting the desired assets and going file -> export selected.
Awesome! Thanks everyone for your replies This is gonna seriously simplify my level design process.
Apparently I was not aware of that. Thanks for mentioning it.