EZiniT .

Ah OK I see,

This is a very odd way of modelling since snapping generally requires "something" to snap too maintaining good topology (in this case the surface is a separate plane, even merged) being that this is **Houdini** if this method is really needed which would be rare then a quick wrangle to get an accurate intersection of the plane in the direction required to move the points in would do the job.

Not a fan of wrangles?....the "ray" node can be used too.

: )

Cut "Boolean" in this example, the size required from a converted heightfield, then a bound node around the result.

Not being very familiar with Blender myself are you trying to do you something like this?

Snapping in Houdini is really good but can be confusing and unintuitive at first....it's actually surprising just how many options and methods are available.

Basic primitive snapping (left of viewport)....right click the icon.

Also check out https://www.sidefx.com/docs/houdini/model/aids.html [www.sidefx.com] for ways to custom align handles too.
(you can align anything really easy, object , point etc but also and more importantly the *pivot* as well using this method)

A couple of gotchas.

1, Right click the handle and check the align option, set it to the required options.....world, component etc
(or press "m" on the keyboard to cycle options)

2, Sometimes working on a node with a pivot parameter is required, edit , transform etc....hard to edit a pivot position with nodes that don't have one right?