Can I back up a single folder on time machine? Basically, I do a lot of work from home, some of which is confidential work. My company has a policy which restricts me from using any form of 'Cloud' to back my files up, so I have set up my time machine to a partition drive on a work server. This however tries to back up my whole Macbook, but I only want to back up the folder which contains my work. 

Is there anyway I can set it up to just back up the single folder, as the partition will not have enough space to back my whole Macbook up, and I also have personal files on which would not be required.
You can specify folders to be excluded from your Time Machine backup, specifically, you could specify everything BUT your specific files. You can access this by going to system preferences > time machine > options.

For example, I have an SD card that's always in my MacBook Air missing from my time machine backup, because I prefer to keep that separated. So I added that device as excluded.