When I choose Display Filter under Edit > Part1 > Common > Control Assign
Try actually going to PART 1's Control Set (you are likely viewing the upper Common/Audio Control Sets... and not Part 1... here’s how to know:
From the HOME screen
Press the [PART SELECT_MUTE/SOLO] button on the far right front panel
Select "PART 1"
Press [EDIT]
Touch "Mod/Control" > "Control Assign"
Now you will be viewing the PART 1 Control Assignment...
The top line of the screen (which always shows exactly 'where' you are) will read "Edit - Part 1 - Common"
As you have noticed the available Controllers are different for the "Edit - Common/Audio" level of the architecture and the "Edit - Part X - Common" level of the architecture.
On the upper "Common/Audio" level is where you can affect ALL Parts - what is available is the Super Knob's 8 (Common) Assign Knobs 1-8, Motion Sequence Lane 1-4, Envelope Follower 1-16, AD, Master. The upper level is over ALL the Parts together, the entire Performance... here you are assigning control over things like the System Effects (Rev, Var), the Master FX, the Master EQ, the A/D Input, the Insertion Effects assigned to the A/D Input. Example, if you assigned a control to change “Reverb Time” (as the Destination parameter) you can understand that all Parts would be affected. Each Part has a Rev Send amount (that is a Part parameter) to the Reverb... but all Parts would share the result of a change in the Rev Time.
On the PART level is where your ‘usual suspects’ (standard Controllers are found): PB, MW, Aftertouch, Foot Control 1/2, Foot Switch, Ribbon, Breath Controller, (Part) Assign Knobs 1-8, Assign Switch 1/2, Motion Sequence Lane 1-4, Envelope Follower 1-16, AD, Master. The Part level is for just the selected Part. The parameter Destinations are per Part — and this is the real power of this engine — each Part has its own 16 Source/Destination Control Sets. This means you can define using the Curve, Polarity, Ratio, and ‘shaper’ Parameter how the control is applied.