To import into your scene go to File>Append, navigate to .blend files folder, open the file, open "Group" folder, then double-click on the name of the group and append.
2objects (in one group for linking Betula (14.5m))
Betula_0601(14.5m) (left part)
Betula_0602(14.5m) (right part)
Or you can select it and copy it using CTRL+C and in your scene pressing CTRL+V.
Please note that this scene contains textures from Poliigon.com and Vitaly - Textures may not be redistributed
HDRI maps are from HDRI Haven