A a new user, I have searched for hours for an answer. In classical guitar and for any finger style guitar, the bass and chords/melody are all written on the one staff.
I am trying to work out how this is done in Dorico, with independent separate note lengths for each.
I imported an XML file from Musescore, but don’t know how to create the same in Dorico SE ?
These are separate voices.
https://steinberg.help/dorico/v3/en/dorico/topics/write_mode/write_mode_voices_inputting_multiple_t.html?hl=voices
Great, thanks.
Please don’t do that. Post on the forum!
I’m sorry… I thought I did ?
I just mean, next time don’t waste hours searching for an answer; we’re here to help! 
I think the more precise answer is not to search for hours. Do a quick search on likely terms, sure, and then feel free to ask here.
If you are notating music for guitar, you may find the various options in Notation Options quite helpful. As so much guitar music has the bass note sharing its pitch with an upper voice, these settings can save a lot of time - see attached.
Hope that helps.
This might be useful also, if you have not seen it:
My mistake, I thought you were saying I had posted in the wrong place.
Yes, using different voices on the same staff. I didn’t know you could do that… but it all makes perfect sense now.
Cheers