Could you attach a picture of the layout you need?

They are in the Bravura font. Insert it as a text expression. A utility like PopChar https://www.ergonis.com/products/popcharx/ is invaluable for things like this!

Hi Mike

Bravura is a free font. You can get it at https://github.com/steinbergmedia/bravura

Download and install the font.

To use it:

In Finale, select the Text tool, and double-click where you want the text frame. Open PopChar, find the character in the Bravura font, and click on it. It will be wrong, in the score. Select that wrong character, go to the Text menu > Font Settings...  In the next window, choose the Bravura font, and play around with the size until you like it.

It sounds complicated. But after you’ve done it a couple of times, it’s faster to do than to describe.

Well, what can I say but Thank You so much Mike, you have pulled me out of the treacle - yet again!! This is not the first time you have helped me over the years and I am truly grateful!! Bless you!

To Peter Thomsen, as you can see in the meantime Mike has given me the solution but thank you for taking the time to respond to me!

The Bravura link doesn't work.  It opens a page which does not contain the file.

If you download the Dorico free trial, it will include the latest versions of Bravura and the Pentaluma (handwritten) font.

You can then uninstall the Dorico demo.

If you don't want to download anything, here's another idea:

I searched on google images for the arrows, and found a graphic of them. Then I screenshot the image and cropped it till it was just the arrows. Then, I went to expression, expression designer, miscellaneous, create misc. expression. I clicked shape, then create. In the box, you'll see a box with three shapes; click on that. Then you can import the graphic that you screenshot and put it directly in your score. Worked for me!

Cheers, Robert

Oh, and the box with three shapes have shapes that are blue, red, and yellow - the last one in the series.

Nothing like reviving a four year old thread that was started for Finale 26…

The normal tool for this has always been the Divisi Tool where you can design your own variants to suit the situation as you please.

https://usermanuals.finalemusic.com/FinaleMac/Content/Finale/Divisi.htm 

Jumping to the present: The current version of Finale is 27 with full SMuFL font support including Bravura, the font that started it all. For those who want to use it, Peter's suggestion to download Dorico is the best. Bravura and Bravura Text are not sandbagged in Mac or Win and are available to all apps that support SMuFL. Don't want Dorico? Delete it after installation—the fonts remain.

Using a custom graphic is always an option but not as flexible as others.

Mike H.,
Divisi is different from splitting or joining staves, which was the OPs request. Yes, the brackets are fine for showing divisi in parts (and I wish more publishers used them) but not for this purpose.

From the top of that page:

Interesting. I didn’t read it the same way you did. Yes, if the sopranos were splitting into two parts on the same staff, then the divisi “vee” would go at the end of the music, inside the staff. But if they were splitting into two staves, then the larger arrows would be used.