I'm having an issue with my edit form combo boxes

[Endowanabe]

Hello everyone,

I'm currently stuck on an issue with my cascading combo boxes in an edit form. So, I have two large data list that are connected, the incoming list is "Complete List"(1,700 items) which is connected to the combo boxes, and the other list "Uploaded List"(700 items) is what the edit form submits the information to. So, I have three combo boxes that are involved in the issue, but only one that's a problem. I have the parent combo box "Dye", the first child combo box "Core", and the second child combo box "Parts". So, I can connect "Core" to "Dye" and "Parts" to "Dye", but I cannot get "Parts" to filter through "Core".
I have the "Dye" item property as :

Sort(Distinct('ALL PM PARTS LIST', Title),Value)
I have the "Core" item property as : 

Distinct(Filter('ALL PM PARTS LIST',Title=cbxDye.Selected.Value),Core)
And for some reason I cannot get "Parts" to work with "Core". I should note that the column lists are as follows: "Dye" is a Title column, and "Core" and "Part" are both choice columns. I'm forced to use the distinct function to retrieve the full list of the items needed, I can use the function :

Distinct(Filter('ALL PM PARTS LIST',Title=cbxDye.Selected.Value),Parts)

For my "Parts" item property, but it doesn't allow me to search or narrow down the choices from the "Core" list like I need. I can make do with either a StartsWith function or if it will just filter through both "Dye" and "Core". 
Thank you all in advance!

[Endowanabe]

First Combo Box - "Die" Items = 

Distinct('ALL PM PARTS LIST', Title);

Second Combo Box - "Core" Items = 

Distinct( Filter( 'ALL PM PARTS LIST', Title = cbxDie.Selected.Value), Core.Value);

Third Combo Box - "Parts: YNA" Items =

Distinct(Filter('ALL PM PARTS LIST',

Title.Value = cbxDie.Selected.Value && Core.Value = cbxCore.Selected.Value), 'Part: YNA');

All Combo Boxes only allow single values. 

I'm attaching images for a better visualisation. 

[WarrenBelz · Accepted solution]

Hi @Endowanabe ,

If 'Part: YNA' is a Choice column you need

Distinct(
   Filter(
      'ALL PM PARTS LIST',
      Title.Value = cbxDie.Selected.Value && 
      Core.Value = cbxCore.Selected.Value
   ), 
   'Part: YNA'.Value
);

The error you attached is related to DataCardValue13, which is not mentioned anywhere in your code.

[Endowanabe]

DataCardValue13, was the Combo Box for 'Part: YNA', I'm not sure if it would matter, but when I imported the list from Excel into Sharepoint, it only allowed me to upload it as 'Single Text Line' Or 'Multiple Text Line', but I manually changed it to 'Choice' through list settings.