The capital structure explains who gets paid first in the case of a company wind up. Generally, debt is paid off first before equity. Hybrids usually get paid after subordinated debt as they are securities with both debt and equity. They tend to fall under debt and above equity in the capital structure. This means that in the event of a wind-up hybrid investors will receive their money if there are leftover funds after all senior and subordinate debt is paid off to creditors.
Paid off first Paid off last
Senior secured debt -> senior debt -> subordinated debt -> hybrids -> ordinary shares