Extracting 5.1 into Stereo Front, Stereo Surround, LFM and Middle

[yoeymeme]

u/echo off
ffmpeg -i input.ac3 -filter_complex "channelsplit=channel_layout=5.1[FL][FR][LFE][BL][BR]"

[BL][BR]amerge=inputs=2,pan=stereo|c0=c0+c1"[stereo_surround]"
[FL][FR]amerge=inputs=2,pan=stereo|c0=c0+c1"[stereo]"

-map "[stereo_surround]" -c:a aac -b:a 192k stereo_surround.aac
-map "[stereo]" -c:a aac -b:a 192k stereo.aac
-map "[FC]" -c:a aac -b:a 192k front_center.aac
-map "[LFE]" -c:a aac -b:a 192k low_frequency_effects.aac

pause

Im attempting tryna seperate the 5.1 into different tracks, i was able to export them sepratly into mono, but how do i make the FL and FR stereo, the BL BR stereo without getting the error

Filter channelsplit:BL has an unconnected output
[BL][BR]amerge=inputs=2,pan=stereo|c0=c0+c1"[stereo_surround]"
'[BL][BR]amerge' is not recognized as an internal or external command,
operable program or batch file.
[FL][FR]amerge=inputs=2,pan=stereo|c0=c0+c1"[stereo]"
'[FL][FR]amerge' is not recognized as an internal or external command,
operable program or batch file.
-map "[stereo_surround]" -c:a aac -b:a 192k stereo_surround.aac
'-map' is not recognized as an internal or external command,
operable program or batch file.
-map "[stereo]" -c:a aac -b:a 192k stereo.aac
'-map' is not recognized as an internal or external command,
operable program or batch file.
-map "[FC]" -c:a aac -b:a 192k front_center.aac
'-map' is not recognized as an internal or external command,
operable program or batch file.
-map "[LFE]" -c:a aac -b:a 192k low_frequency_effects.aac
'-map' is not recognized as an internal or external command,
operable program or batch file.

[pandy]

You need to perform processing (like merge, channel operations) within filter_complex - something like:

-filter_complex "channelsplit=channel_layout=5.1[FL][FR][LFE][BL][BR];[FL][FR]join=inputs=2:channel_layout=2.0[stereo];[BL][BR]join=inputs=2:channel_layout=2.0[stereo_surround]"