Having trouble finding mining nodes

[Jojoya]

You should already be seeing the level 30 nodes. Level 35 nodes (with the 31-35 items) won't be visible until you reach level 30. Nodes are always a multiple of 5.

You always need to reach the level of the highest currently visible nodes before the next set of nodes will be visible. This is a slight upgrade this expansion, previously you would have had to wait an additional level (couldn't see level 35 until you reached level 31).

At level 46, you will gain Truth of the Mountains which will allow you to see level 50 unspoiled (timed) nodes when you have it enabled. Similar to normal nodes, once you reach level 55 you'll be able to see level 60 unspoiled nodes, etc. At level 60, you gain a trait that will automatically enable Truth of the Mountains (no more need to remember to toggle it).

Also at level 60, legendary nodes (also timed) are introduced. They will only be visible if you have purchased and used the required Folklore tome for the zone where the node is located.