default vesamenu.c32
prompt 0
MENU INCLUDE vesamenu/vesamenu02.cfg

MENU TITLE PXE Boot main menu
MENU AUTOBOOT Start local system in # seconds.
MENU TABMSG Press [TAB] to change settings.

LABEL local
        MENU LABEL Boot locally
        MENU default
        LOCALBOOT 0
        TIMEOUT 60
        TOTALTIMEOUT 9000

MENU SEPARATOR

LABEL linux
        MENU LABEL ^linux
        KERNEL vesamenu.c32
        APPEND pxelinux.cfg/linux

LABEL windows
        MENU LABEL ^windows
        KERNEL vesamenu.c32
        APPEND pxelinux.cfg/windows

LABEL other
        MENU LABEL ^other
        KERNEL vesamenu.c32
        APPEND pxelinux.cfg/other



Then:
MENU TITLE PXE LINUX

LABEL -
        MENU LABEL ^Back
        KERNEL vesamenu.c32
        APPEND pxelinux.cfg/default

LABEL Ubuntu
        MENU LABEL ^Ubuntu
        KERNEL vesamenu.c32
        APPEND pxelinux.cfg/ubuntu

LABEL CentOs
        MENU LABEL ^CentOs
        KERNEL vesamenu.c32
        APPEND pxelinux.cfg/centos

LABEL Mint
        MENU LABEL ^Mint
        KERNEL vesamenu.c32
        APPEND pxelinux.cfg/mint

For ubuntu:
MENU TITLE PXE UBUNTU

LABEL -
        MENU LABEL ^Back
        KERNEL vesamenu.c32
        APPEND pxelinux.cfg/linux

LABEL Ubuntu.18.04.3-server
        MENU LABEL ^Ubuntu.18.04.3-server
        TEXT HELP
        Offline install
        ENDTEXT
        kernel ISOs/pxe/linux/ubuntu/ubuntu-18.04.3-server-amd64/install/netboot/ubuntu-installer/amd64/linux
        append vga=normal initrd=ISOs/pxe/linux/ubuntu/ubuntu-18.04.3-server-amd64/install/netboot/ubuntu-installer/amd64/initrd.gz ramdisk_size=16432 root=/dev/rd/0 rw --

For mint I think this one:
LABEL 6
        MENU LABEL ^5) Mint 19 mate v2
        TEXT HELP
        Idk anymore
        ENDTEXT
        KERNEL ISOs/pxe/linux/mint/Mint19MateV2/casper/vmlinuz
        APPEND boot=casper initrd=ISOs/pxe/linux/mint/Mint19MateV2/casper/initrd.lz netboot=nfs nfsroot=172.16.0.3:/var/lib/tftpboot/ISOs/pxe/linux/mint/Mint19MateV2 locale=de_DE keymap=de biosdevname=0 net.ifnames=0 systemd.mask=tmp.mount vga=771 ip=dhcp --