How do you find buried vias in Altium Designer?
In Altium Designer, have the PCB file open.


In the bottom right-hand corner select the PCB menu.
Select PCB from the menu.




The PCB tab opens and by default docks to the left-hand side.


Open the dropdown menu.
Select Hole Size Editor.





Find an entry that doesn't connect to either the Top Layer or Bottom Layer and select the check box.




The burried vias will show up in the areas highlighted above, if any.