triple apogiatura or grupeto in double strings
Dear Sirs In a song we are editing, it has a triple apogiatura, or a grupeto with two overlapping notes, that is, in double strings. I do not know Musescore program resources to do this, you have an orientation on how to do it ?. To facilitate the understanding I will send an attachment of a piece of music where the second staff, in the first bar has this apogiatura or grupeto 
Comments
This?
Grace note chords are built up just like regular chords:
1. Enter the first note of the chord as shown above
2. Select this first grace note and enter subsequent notes as you would for any other regular chord (i.e. Shift+A...G).
https://musescore.org/en/handbook/grace-notes#grace_note
It looks like you are talking about the first measure of the second line.
To enter the apogiatura as a chord, enter one of the line of notes (I recommend the bottom line of notes) as normal. You will then need to select each note and use shift+ a note name to add to the chord as you would a normal chord such as in the previous measure. Let me know if this is not clear and I will explain step by step if needed.
In reply to It looks like you are… by mike320
Mike could not do it. I put the bottom note when I press the shift to add the top note, the musescore cursor goes to the actual note
In reply to Mike could not do it. I put… by Roberto Dal Medico
Shift+A (B/C/D ecc.) not in input mode
copy&paste?
In reply to Shift+A (B/C/D ecc.)… by Shoichi
Shoichi is correct. After you enter the first 3 grace notes, you need to turn off note input mode every time it turns itself on or switch to repitch mode by clicking the fancy N below the new score button and select Re-pitch. Remember to turn note input mode back to Step time when you are done.
In reply to Shoichi is correct. After… by mike320
SHOICHI AND MIKE320 I'M VERY THANKFUL FOR THE GUIDELINES