There are two approaches to do what you want:
- Create a new column and just copy over the labels you want to show and leave the others blank. Then you can use that column as a passthrough to your node label.
- I would just select the nodes you want to show the labels for, then invert the selection (Select->Nodes->Invert node selection). Now the nodes you want hide the labels for are selected. Then, in the Styles panel, go to the Label row and click on the Byp. (Bypass) column. That will bring up a text box where you can enter a new node label. Just hit OK and the labels for those nodes will vanish.