kiryuha,
The feature you are looking for is an Eclipse feature and Eclipse currently does not support the code folding for control flow statements.Since MyEclipse is based on Eclipse, the feature is not supported in MyEclipse too.
You can raise an enhancement request in the Eclipse bugzilla to add the support: https://bugs.eclipse.org/bugs/
You can also check if there are any third party plugins compatible with Eclipse which provide the code folding options you are looking for and try installing to MyEclipse and see how it works.
Let us know if you have any questions.
–Swapna
MyEclipse Support