Fixing things in a dream signifies many things, but often it indicates that you are trying to make something better or repair an error that was made. For example, if you were trying to fix a wardrobe door in your dream this could represent feeling overwhelmed by obstacles at work or it could signify a missed opportunity with someone who is important to you.
Fixing somethings in a dream also represents getting back on track after something has gone wrong. If you dreamed of fixing your car for example it could indicate that you have made too many mistakes lately and need to focus more on the important parts of your life.
If a dreamer sees objects that need fixing and they are able to do this, then the dream may be a reflection on how they want to mend things in their professional or personal life.