How do make a record creation step precompile a table with "Link from?"

Sounds like you have two questions. We will start with just the first one.

When I insert a new replacement part I would like the machine already inserted in the intervention on the replacement parts table to be filled in automatically,

 Let me see if I understand your structure. You have:

Machines (table)

Replacement Parts (table)

Interventions (table)

Machines and Replacement Parts are linked (1:N)

Interventions and Replacement Parts are linked (1:N)

Now how do you use the links to get to the data you need?

How the above system works is that machine1 can have part1 and part2 linked to it. Machine2 can have part1 and part 3, etc.

Let's say you create a new intervention record. Then you link the replacement parts used in the intervention. For this example you will use only use part1.

Using the intervention example, if you link part1 to intervention1 and then create a formula field with:

'Replacement Parts'.Machine.Name

You should see the names of machine1 and machine2, since both machines are linked to part1. A reminder that there is a many to 1 relationship between parts and machines. Ninox doesn't know which record you need to show so it will always show you all related records.

Which means you need to figure out a way to filter which machine the intervention was for.

One way is to use put a reference field to Machines in Interventions then you can put a constraints based on Replacement Part so only related Machines show up.

Another is to use a dynamic choice field that uses the data in Replacement Parts to limit what machines are available.

Another is to create another table (call it Intervention Items) then create a reference field to Machines and Replacement Parts. This will allow you to also track the same part for different machines in the same intervention. If that happens in your work flow.

Or

If you use the Replacement Parts table as a 1:1 relationship then you can just use the formula from above.