Hi,
A Peripheral device is essentially link-layer slave, so it is not expected to initiate connections. If device that implements both Peripheral and Central roles is required, it is possible to switch roles while program runs.
Basically, if you want Peripheral device to control whether it permits connection or not, you have such option as altering whitelist, or just disabling advertising altogether (you can disable/enable it as you want, at any time).
BR,
Oleg
