1 cup crushed ice
1 1/2 fluid ounces anise-flavored liqueur (such as Herbsaint®)
1/2 fluid ounce anisette liqueur (such as Sambuca®)
2 fluid ounces club soda, or more as needed
Fill a highball glass with crushed ice. Pour anise-flavored liqueur and anisette liqueur over ice; top with club soda. Stir to combine.