If you have an other system on your computer you can use Grub for select the OS you want to run…
Example:
To boot Haiku from grub I had to edit a configuration file of Grub in my Debian (second OS on my computer)…In this config file the Grub menu must point to the Haiku partition. You can use the software Grub-Customizer in linux is more easy.
An other option is to use the menu from the Haiku Installer. (in left up corner of Haiku Installer) and set the booting partitions of your OS.
So…Maybe this topic will be help you about Grub configuration file.
Grub is generally given with a Linux distribution…
Dual boot with Grub
But If you have only installed Haiku on your system…I don’t really understand the trouble because I think Haiku load directly after a fresh install.
Note: You must install the Haiku system on the BE FileSystem partition you had created and you need to formated this Be partition before installing the Haiku system.