Is there any query/code that can find common values in records?

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MySQL

Would you Please guide me (maybe Simple and fast query if there is or some fast code) to convert my CSV data file (with commas separation):

1,A,C,Z,F,G
2,G,Q,R,C,
3,Z,G,Q,
4,C,F,
5,O,P,
6,O,X,Y,J,
7,A,P,X,

I have this table with ~1,000,000 records like these 7 records that you see (**In real Database A,B,C,... are words in string**), Records 1 and 2 are common in G and C value and 2,3 and 1,3 and ...

I want to sync records if they have at least two common value like Records 1 & 2,3,4 (but record 5,6,7 haven't at least 2 shared values with others) and generate a list like this:

1 A C Z F G Q R
2 G Q R C A Z F
3 Z G Q A C F R
4 C F A Z G Q R
5 O P
6 O X Y J
7 A P X

At the end we must have 4 same records if we sort data and one others without sync:

1 A C F G Q R Z
2 A C F G Q R Z
3 A C F G Q R Z
4 A C F G Q R Z
5 O P
6 J O X Y
7 A P X

Maybe I do not use good term for my meaning, please see:

1 A C Z F G
2 G Q R C

record 1 has C and G common with Record 2 now 1 has not R and Q thus we must have 1 A C Z F G + Q and R and Record 2 has not A,Z and F thus we must have: 2 G Q R C + A,Z and F thus at the end we have:

1 A C Z F G Q R
2 G Q R C A Z F

I need all records Respectively in the queue from top to bottom. wrote a delphi code but it is so slow. Someone suggest me this groovy code:

def f=[:]
    new File('Data.csv').readLines().each{
    def items=it.split(',')
    def name
    items.eachWithIndex { String entry, int i ->
    if(i==0){
    name=entry
    }
    else if(entry){
    if(!f[entry])
    f[entry]=[]
    f[entry]<<name
    }
    }
    
    }
    f.findAll {it.value.size()>1}

It is very fast (because of using a map file I think), but It only finds the common values.
Please give me any help or suggestion.
Thank you

What I have tried:

find common values by code or a query in any database