Can I create search nodes using Tana Paste?

Yes you can: We have a basic syntax for this which you can read about here.

Example of a task search:

%%tana%%
- %%search%% Fei's tasks
  - OR::
    - [[#task]]
    - [[#CS todo]]
  - Assigned to::
    - [[Fei-Ling Tseng]]
  - NOT DONE

When I paste the above, this is the result: