With the release of HFM 18.104.22.168.000, the Rules Editor is no longer available. Per the readme file (http://docs.oracle.com/cd/E17236_01/epm.1112/hfm_1112200_readme.pdf), you will need to download and install Notepad++, which is a free product.
Per the documentation (http://docs.oracle.com/cd/E17236_01/epm.1112/hfm_admin.pdf), see the section called "Creating Rules in Notepad ++". You will need to import the HFMRules.xml file, which is located in the HFM utilities folder, into Notepad++ to get the functionality into Notepad++.
Once you have downloaded and installed Notepad++, launch the product.
- Go to Settings > Import > Import style theme(s)...
- Browse to the HFM utilities directory (for example - C:\Oracle\Middleware\EPMSystem11R1\products\FinancialManagement\Utilities), select HFMRules.xml and click Open
- You should see it under the Language menu as a user-defined language