I'm not totally clear on exactly what you are trying to create on your layout.
I would like the user interface to select a machine type, be given a list of machines that meet that criteria,
In addition to producing a conditional value list that could also be a list of records from Machines shown in a portal or a find could be performed that pulls up a list view of all the machines of that type. I'm not sure how/why you'd need a value list of such machines in this scenario. Are you just finding records or are you creating a new record. And if you are creating a new record, is it a new machine or a new issue record?
On the layout, the user would select from a list of machine types that he would be working on. Then, a list of machines that fit the type would be chosen. Then, a common issue relating to that machine type would be chosen.
This info would all be entered into a record in a table called "repair actions" which is related to "machines" which is related to another table "common issues".
Thus, you are creating a new record in Repair Actions that is linked both to a specific Machine and a Specific common issue (if one exists).
I would not use a Machine name for the needed relationships. Names are subject to change and vulnerable to data entry errors. If you have to change a name for either reason in your database, you may end up losing the link to existing related records as they match by the original name. Use an auto-entered ID such as a serial number instead.
This suggests the following relationships:
Both CommonIssues|Repair and CommonIssues|Type would be Tutorial: What are Table Occurrences? with the same data source table.
The match fields:
CommonIssues|Repair::__pkCIssueID = RepairAction::_fkCIssueID
Machines::__pkMachineID = RepairActions::_fkMachineID
MachineTypes::__pkMachineTypeID = Machines::_fkMachineTypeID
MachineTypes::__pkMachineTypeID = CommonIssues|Type::_fkMachineTypeID
But for a conditional value list of Machines for a selected type, we'd need to add in another occurrence of Machines and MachineTypes like this:
RepairActions::MachineTypeID = MachineTypes|VL::__pkMachineTypeID
MachineTypes|VL::__pkMachineTypeID = Machines|VL::_fkMachineTypeID
Then your CVL of Machines can be setup on RepairActions::_fkMachineID to list values from Machines|VL, Include only related values starting from Repair Action.
Your CVL of CommonIssues would be set up on RepairActions::_fkCIssuesID to list values from CommonIssues|Type, Include only related values starting from RepairActions.
For an explanation of the notation that I am using, see the first post of: Common Forum Relationship and Field Notations Explained
And You might not need that CVL of machines if you set up a portal to RepairActions on a Machines layout. Then you might perform a find to find a machine and fill out the repair action data directly in a row of the portal.
You added MachineTypes as a table, i am assuming. Or is it a TO of Machines, self related?
I set it up as a table. If you are going to have a value list of Machine Types, a table of the same would make sense to me, though I suppose that you could manage without it by linking a MachineType field in Machines directly to the TO of common issues.