When using the mTick app having chosen a developments, press 
top right.
Sort order is the second field down.
Press on the ‘Sort By’ entry (highlighted above)
You will be shown your current Sort By sequence as below.
The numeric number shows the priority in the sort sequence whilst the triangle gives the Ascending / Descending order.
Press on the items to remove/add them and the triangle to change order.
Press done when you are happy with the sequence.
You don't have to keep the three in the example above. Below I removed two of the entries leaving just Plot Number.