Frustrating light switch swap

[whydidistartthis]

Im at my whits end and I wonder if anyone can shine some light on this for me before I fully admit defeat.

Here's what I've Got at the moment

1 x upstairs 2 gang, 2 way switch which controls the landing light (controlled at the bottom of the stairs with another switch) and bathroom light.

I'm wanting to swap this for a switch (for the landing light) and a dimmer for the bathroom spots (don't ask why the misses was moaning it was too bright and didn't take my suggestion to wear sunglasses very well)

Having taken the switch off I have the following on the old switch:

2 x twin and earth cables and a 4 core coming into the back box, 2 together (twin and earth and 4 core) and one to the right which I can only assume is the bathroom light as it's closest to the bathroom door

These connect as follows to:

L1 top (labelled COM) - potentially bathroom wire

L2 top (labelled 1 way) - A pair, black (brown sleeve) & Brown wire (one from each of the left twin and earth and 4 core cables)

L3 top - a pair, grey (brown sleeve) and brown wire (one from each twin and earth and 4 core)

L1 bottom (also labeled COM) - (from 4 core)
L2 bottom - potentially bathroom
L3 bottom - empty


I'm wanting to put these into the following

New switch:
COM -
L1 -
L2 -

Dimmer:
C
L1
L2


My understanding is that I only need a feed into C (link wire from com?) and L1 to the lights going to the bathroom lights in the dimmer side
But I have no bloody clue about where these others are meant to go I've tried a couple of combinations but can't get both the down stairs and upstairs switches working together which is what I wanted to do before figuring out the dimmer part

I've attached photos, any help at all would be greatly appreciated

 

[flameport]

Two separate switches, A and B separated by the red line.

The wires for each transfer to the new switches to the same connections.

Wires for A to the new dimmer.
Wires for B to the new switch.

The only minor difference is that C on the new is L1 on the old.


Nothing else is changed, you do not need to add any wires or links or anything else.

 

[whydidistartthis]

Bloody hell, so nothing in C on the dimmer then??

 

[flameport]

Dimmer is C and L1 instead of L1 L2
The other one is C, L1, L2 instead of L1, L2 L3

 

[whydidistartthis]

Well bigger me you've done it

 

[SUNRAY]

EDIT: Damm it took 7 minutes to open PC and do this

 

[whydidistartthis]

I appreciate your help guys you've saved me no end of earache off the misses

 

[whydidistartthis]

View attachment 413932

Two separate switches, A and B separated by the red line.

The wires for each transfer to the new switches to the same connections.

Wires for A to the new dimmer.
Wires for B to the new switch.

The only minor difference is that C on the new is L1 on the old.


Nothing else is changed, you do not need to add any wires or links or anything else.

While we are on the subject of dimmers, now you've kindly managed to get this working I was wondering

I have a spare switch and back box, if I were to install that next to this dimmer switch and have the landing light off that and use the switch located on the dimmer for a full brightness regular bathroom switch and the misses can use the dimmer, would that be possible?

I'm guessing if I move all B over to the new switch, would there be a way of linking the switch next to the dimmer so solely control the bathroom light? Almost by passing the dimmer