You can input both single-note and multi-note tremolos using the repeats popover, both during note input and by adding them to existing notes.
Procedure
Result
Single-note tremolos are input on the selected notes with the number of tremolo strokes specified. They appear on all notes in tie chains.
Tremolos with release show single-note tremolo strokes on all notes in tie chains apart from the last note. Tremolos with attack show single-note tremolo strokes on all notes in tie chains apart from the first note.
Multi-note tremolos with the number of tremolo strokes specified are input between selected individual notes and the notes immediately after them, or between selected pairs of notes. The notated duration of notes in multi-note tremolos is automatically updated. For example, two quarter notes joined by a multi-note tremolo both appear as half notes.
When tuplets are selected, multi-note tremolos are input across the selected tuplets, with the tremolo strokes positioned in the center of all notes in the tuplet. The tuplet bracket is hidden, and a signpost is shown at the start of each tuplet indicating its ratio.
The appearance of stems in multi-note half note tremolos depends on your setting on the Tremolos page in Engraving Options.
Example
After Completing This Task
You can enable independent voice playback for individual instruments to hear different sounds in different voices simultaneously; for example, if you have tremolos in one voice and slurs in another voice.