Many of the tools available for general users, is limited or difficult to find for use in linux. 

I use tvheadend serving to kodi, an OSMC Vero V box. For well formed m3u files, I use [https://github.com/bebo-dot-dev/m3u-epg-editor] This works very well for trimming your playlist/xml files to submit to tvh, the playlist is trimmed and associated unwanted guide data is eliminated as well. 

A lot of the recommended providers have lists that are thousands of channels, with associated xml guide data, some may have well formed data, most don't, there are specifications for m3u8 and xmltv, but most don't follow the guidelines. 

I recently subscribed to one of the services on z2, I received login/download info, and proceeded to input the info in a second tool:[https://github.com/Cyogenus/Xtream-m3u_plus-IPTV-Player-by-My-1]  This is an XCIPTV, program, that allows one to input the login info in and view the channels via your preferred external program, either VLC or SMPlayer, you are able to view channels/groups, saves the guide xml data, but not the m3u, good for a first check, for connect ability and stream availability.  I next loaded the info from the above, into the m3u-epg-editor, what a mess, very little to no separation or segregation of channels, as an example, US Entertainment, had EVERY LOCAL NBC,CBS,ABC,CW, as well as others,from New York to Los Angeles, contained within, also had MANY sports categories within, in short a jumbled, mixed category of channels.I worked on this list for hours, attempting to find some happy medium, between what I wanted and which category I needed to subscribe to. I failed to find the needed wanted channels/categories, that didn't have MANY unwanted categories/channels, I could request a group/channel, but there so many associated channels, I spent hours getting rid of unwanted things. 

Below is an AI generated python3 script to run on your m3u file, it searches the list and associates groups to channels, first looks for the groups, then separates the channels to which groups it belongs to. 

<import re

def parse_m3u8(file_path):
"""Parse the M3U8 file to separate groups and channels."""
groups = {}
with open(file_path, 'r', encoding='utf-8') as f:
    lines = f.readlines()

# Regex patterns to capture group and channel information
group_pattern = re.compile(r'group-title="([^"]+)"')
channel_pattern = re.compile(r'tvg-name="([^"]+)"')

current_group = None
for line in lines:
    # Check if the line contains a group-title
    group_match = group_pattern.search(line)
    if group_match:
        current_group = group_match.group(1)
        if current_group not in groups:
            groups[current_group] = []

    # Check if the line contains a tvg-name (channel name)
    channel_match = channel_pattern.search(line)
    if channel_match and current_group:
        channel_name = channel_match.group(1)
        groups[current_group].append(channel_name)

return groups

def save_groups_to_file(groups, output_file):
"""Save the groups and their associated channels to an output file."""
with open(output_file, 'w', encoding='utf-8') as f:
    for group, channels in groups.items():
        f.write(f"Group: {group}\n")
        for channel in channels:
            f.write(f"  Channel: {channel}\n")
        f.write("\n")

def main():
# Path to the M3U8 file
input_file = "/CHANGE/TO/YOUR/M3U/LOCATION.m3u8"

# Output file where the groups and channels will be saved
output_file = "/home/CHANGE/TO/YOUR/GROUPS_and_CHANNELS.txt"

# Parse the M3U8 file to separate groups and channels
groups = parse_m3u8(input_file)

# Save the result to an output file
save_groups_to_file(groups, output_file)
print(f"Groups and channels have been saved to {output_file}")

if __name__ == "__main__":
main()