Picklist Value Rendering Based on Text Field Value

I imagine someone has asked this before, but I can’t seem to find it after looking through a few dozen topics.

Here’s the scenario:

• Field A is a text field which can have values such as Tier 0, Tier 1, Tier, 2, etc. populated by WF rules
• Field B is a picklist for upgrading the above Tiers with 2 values, Tier 3 and Tier 4
• Tier 3 should only be available for select if Field A is Tier 2, or if Field B itself is Tier 3 (so we can unselect the upgrade)
• Tier 4 should always be selectable

We’ve used a custom snippet before for picklist rendering, but due to being JS novices, I can’t seem to figure out how to incorporate a second field.

This is what we previously used for Lead Status, which was only rendering based on its own values:

var field = arguments[0],    //value = skuid.utils.decodeHTML(arguments[1]);
    value = arguments[1],
    $ = skuid.$;
    
var picklistEntries = field.metadata.picklistEntries;

// If value is Reached Out or Engaged,
// then only show those values
if ($.inArray(value,[‘Reached Out’,‘Engaged’])!==-1) {
    picklistEntries.length = 0;    
    picklistEntries.push(
        { value: ‘Reached Out’, label: ‘Reached Out’, defaultValue: false, active: true },
        { value: ‘Engaged’, label: ‘Engaged’, defaultValue: false, active: true }
    );
} else if (value===‘Sales Accepted’) {
    picklistEntries.length = 0;   
    picklistEntries.push(
        { value: ‘Sales Accepted’, label: ‘Sales Accepted’, defaultValue: false, active: true },
        { value: ‘Reached Out’, label: ‘Reached Out’, defaultValue: false, active: true },
        { value: ‘Engaged’, label: ‘Engaged’, defaultValue: false, active: true }
    );
}


// Run the standard picklist renderer for the given mode
skuid.ui.fieldRenderers[field.metadata.displaytype]field.mode;  


Where might I start to pull in that Field A value and use that in the logic? (I really this is pretty basic, so thanks in advance)