Broken Triads

It's the question what's your aim:

• If you're talking about arpeggios, select the duration and insert the notes of a chord note for note (the easiest way for me is using shortcuts: https://musescore.org/en/handbook/keyboard-shortcuts#note-input), (for example for C major chord in the basic position: "n" for note input mode, "4" for eight notes, and then in a row the keys "C", "E" and "G".)
• if you're talking about inserting fingering for arpeggios/broken chords see: https://musescore.org/en/handbook/fingering
• if you're talking about a glissando of a chord see: https://musescore.org/en/handbook/arpeggios-and-glissandi

fun pattern for 4 noteminor chords lala